Epigenetic stability in Saffron (Crocus sativus L.) accessions during four consecutive years of cultivation and vegetative propagation under open field conditions

Saffron (Crocus sativus L.) is a sterile species that is vegetatively propagated in the field, year by year, via the\r\nproduction of new corms. While Saffron’s genetic variability is extremely low, phenotypic variation is frequently\r\nobserved in the field and epigenetics could be a possible origin of these alternative phenotypes. Present day\r\nknowledge on Saffron epigenetics is very low or absent. In the present paper, to deepen existing knowledge, we\r\nfocused on the epigenetic differences and stability among 17 Saffron accessions, of different geographic origin,\r\nduring four consecutive years of vegetative propagation under open field conditions. Before the analysis, the\r\nselected accessions have been cultivated in the same field for at least three consecutive years. Despite the low\r\ngenetic variability and the prolonged co-cultivation in the same environment, Methylation-Sensitive Amplified\r\nFragment Length Polymorphism (MS-AFLP) analysis revealed a very high epigenetic difference among accessions,\r\nmaking it possible to discriminate them based on the epigenetic profiles. During the four years of the\r\nstudy, a little variation has been observed within accessions following different patterns, slightly modifying the\r\naccession epigenotypes but not enough to even them to a more uniform profile. These results confirm that, under\r\nnatural conditions, Saffron epigenotypes are highly stable, supporting a role for epigenetics in phenotypic\r\nvariability.